Abstract:
Naomaohu sub-bituminous coal (NMH) was thermally dissolved in isometric methanol/toluene mixed solvent affording soluble portions (SPs) and thermal dissolution residues (R
TD), then hydroconversion of SP
320 was catalyzed over Co/C@N-700 catalyst affording CSP
320. The composition and structural characteristics of SP
320 before and after catalytic hydroconversion were analyzed with a gas chromatograph/mass spectrometer (GC/MS), and pyrolysis reactivity and structural characteristics of NMH and R
TD were characterized with Fourier transform-infrared spectroscopy (FT-IR), thermogravimetry, as well as solid state
13C nuclear magnetic resonance (
13C NMR). The SPs yields increase with increasing temperature, and reach a maximum (36.46%) at 320
oC. GC/MS analysis shows that SP
320 are mainly composed of alkanes, phenols and arenes, and their relative contents are 45.45%, 18.03% and 24.75%, respectively. After catalytic hydroconversion, relative contents of arenes and phenols in CSP
320 decrease to 3.86% and 13.6%, respectively, while those of alkanes and alcohols increase to 66.99% and 9.36%, respectively, and kinds of cycloalkanes increase from 8 to 24. These results indicate that arenes and phenols in SP
320 could be hydrogenated into alkanes and alcohols catalyzed by Co/C@N-700. Compared to NMH, R
TD possesses higher thermal stability, more aromatic carbons, and less carbonyl carbons in its skeleton structure. In addition, intensity of adsorption peaks attributed to O−H, −CH
2−, C=O and C−O−C in the FT-IR spectrum of R
TD are weaker, while adsorption peaks assigned to aromatic C=C are stronger than those of NMH.